The present invention relates to a differential apparatus, and more specifically to a differential apparatus usable in common for two output shafts designed for various type automotive vehicles.
In the differential apparatus for an automotive vehicle, the differential motion (rotation) between two output members (two shafts) is usually larger than that between a differential casing and an output member (shaft). Accordingly, when differential limiting means is provided between the two output shafts, it is possible to obtain not only a relatively large differential limiting force by the differential limiting means of a relatively small size, but also reliable differential limiting characteristics due to an equal transfer ratio on both sides of the output shafts. In the case of the differential apparatus of bevel gear type, however, since side gears are arranged with pinions intervening between the two side gears, it is difficult to directly dispose the differential limiting means between the two side gears, with the result that the differential limiting means is usually disposed between the two output shafts. In this case, however, the length of the output shaft is different from each other on both sides of the differential apparatus, so that there exists a problem in that two output shafts of different lengths are required for the differential apparatus provided with the differential limiting function and therefore it is necessary to change the design of the output shafts whenever mounted on the already existing vehicles having another differential apparatus provided with no differential limiting function.
To overcome the above-mentioned problem, a differential apparatus as shown in FIG. 1 has been proposed in Japanese Published Unexamined (Kokai) Utility Model Application No. 62-126645, in which an intermediate link shaft 211 is provided between the two output shafts 217 and 219. In more detail, in this differential apparatus 201, the differential motion of a bevel gear type differential mechanism 205 is limited by a viscous coupling 203. That is, one side gear 207 is linked with a left side output shaft 217 via a housing 209 of the viscous coupling 203, and the other side gear 213 is linked with a right side output shaft 219 and an intermediate link shaft 211 fixed to a hub 215 of the viscous coupling 203. In this prior art differential apparatus, however, since the intermediate link shaft 211 is disposed between the left side output shafts 217 linked with the side gear 207 and the right side output shaft 219 linked with the side gear 213, a wide space is required between the two output shafts 217 and 219. Further, although the axial length of the output shaft 217 is equal to that of the output shaft 219, the length thereof is relatively short, it is impossible to use the two output shafts of this differential apparatus in common for the two output shafts of other differential apparatuses provided with no differential limiting function, for instance.